This invention relates to a system for sealing the electrical leads of an electric motor at the point where they pass through the shell or housing of the motor. More specifically, this invention relates to a grommet which sealably clamps on the lead wires and which sealingly closes the lead wire passthrough opening in the motor assembly of the motor.
In the operation of electric motors in environments subject to airborne grit or sand particles (such as under desert operating conditions) it is vital that this airborne grit and sand be kept out of the motor so as to protect the motor bearings and other components within the motor. Conventionally, a "totally enclosed" motor is used for this purpose, for example. However, even totally enclosed electric motors must have some means for passing the motor lead wires through the shell of the motor. This is typically accomplished by providing an opening in the motor shell and by installing a wiring bushing in this opening. The bushing commonly has a plurality of passages for the reception of the motor lead wires. These prior art wire bushings, however, did not always seal the lead wires or did not always seal the opening in the motor shell. If the lead wires or the opening are improperly sealed, dirt and other airborne grit can enter the motor which in turn can significantly shorten the service life of the motor. In many instances, the lead wires of the prior art motors were sealed with respect to the bushing and the latter was sealed to the motor shell by means of a hot melt adhesive or potting compound applied to the lead wires so as to seal them. While this potting operation was generally successful in sealing the leads with respect to the bushing, it required a good deal of extra time during assembly of the motor and thus was costly and it was also a messy operation. Still further, these potted lead wires are a hinderance in the field service of these prior motors because it prevents field servicemen from readily removing the wires from the bushing and from reinserting them upon completion of the repair.